Plastic components that make a window frame or sash are typically welded together by miter cutting the components to size, heating the mitered ends and then pressing the heated ends together so that the melted ends bond to each other. This process often squeezes some of the material out from between the two pieces which creates a bead of material, commonly referred to as weld flash, requiring further processing to obtain better appearance as well as removing material which may interfere with further assembly of the window itself such as installing an IG unit into a sash or a sash into a frame.
Further processing can be accomplished using a corner cleaner, a machine that removes the weld flash by means of multiple types of tools such as saw blades, knives, end mills or router bits to cut or abrade away the weld flash where it is not desired. Variances in the dimensions of the profile material and/or misalignment of the two parts during the welding process hamper the ability of the machine to consistently remove the weld flash to controlled dimensions due to profile dimensions changing in the frame extrusion.
U.S. Pat. No. 4,909,892 to Quinn et al concerns an apparatus for simultaneously welding two or more pairs of thermoplastic frame elements. U.S. Pat. No. 4,971,639 to Quinn et al concerns a method and apparatus for welding vinyl window and door frames. These patents are assigned to the assignee of the present invention and are incorporated herein by reference.